Vtol model aircraft

ABSTRACT

A toy model aircraft aims to imitate V-22 Osprey with high emulation by being providing with flight characteristics of V-22 Osprey at a shrunk size of a toy specification. The model aircraft of the invention includes a fuselage, two fixed wings extended outwards from two sides of the fuselage and a tail wing at the tail of the fuselage. Each fixed wing includes a propeller engine installed at a distal end thereof and a rotor. The two rotors of the propeller engines rotating in opposite directions, and the propeller engines are coupled to form an integrated body through a rotary axle mechanism connecting to the wings. The fuselage holds a rotary axle driving means to drive the rotary axle mechanism to rotate and the propeller engines at two ends of the rotary axle mechanism are rotated concurrently between the vertical direction and horizontal direction.

FIELD OF THE INVENTION

The present invention relates to a toy model aircraft and particularlyto a VTOL (vertical take-off and landing) model aircraft having flightcharacteristics of helicopters and fixed-wing aircrafts.

BACKGROUND OF THE INVENTION

Helicopter flies through air buoyancy generated by spinning of rotors.By changing the climbing power and tilted direction of the pulling forceof the rotors, flight conditions of the helicopter can be maintained oraltered. It provides many advantages such as vertical take-off andlanding and hover in the air. But its cruising speed is lower and safetyis less desirable. On the other hand, a fixed-wing aircraft fliesthrough air buoyancy generated by a pressure difference formed by fastairflow passing through the upper and lower sides of airfoils. Bychanging the angles of ailerons, elevators or rudder, it has highercruising speed and safety, but requires longer take-off distance andcannot hover in the air. In 1950s and 1960s, some companies in U.S.,Canada and Europe developed tilted rotor aircrafts that have advantagesof both helicopter and fixed-wing aircraft. Bell helicopter Co. andBoeing helicopter Co. developed a V-22 Osprey multi-purpose aircraftbased on the multi-purpose VTOL aircraft R&D plan (JVX plan) released byU.S. Department of Defense. It is one of few successful cases.

V-22 Osprey also is called tiltrotor aircraft. It has two rotor tiltsystem assemblies which are turnable between the horizontal position andvertical position respectively installed on a tip of a wing which issimilar to the airfoil of the fixed-wing aircraft. When the aircraft isin vertical take-off and landing, the rotor shaft is perpendicular tothe ground surface. The aircraft flies like a transverse helicopter, andalso can hover in the air, or fly forwards and backwards and crab. Afterit has reached a certain flying speed, the rotor shaft can be tiltedforwards for ninety degrees in a horizontal condition, then the rotorscan serve as a pulling propeller. In such a condition, the tilted rotoraircraft can fly in higher speed for longer distance like the fixed-wingaircraft. Thus the tilted rotor aircraft is a unique rotor aircraft withabilities of the helicopter that can perform vertical take-off andlanding and hover in the air, and also with abilities of a turbopropthat can fly in high cruising speed.

Model aircraft has been developed following the real aircraft. As V-22Osprey tiltrotor aircraft is a novel aircraft different from theconventional helicopter or fixed-wing aircraft, to modify V-22 Osprey toa model aircraft is a great challenge. At present, most model aircraftimitating V-22 Osprey merely imitates the profile or provides merelyhelicopter function.

SUMMARY OF THE INVENTION

The present invention aims to provide a model aircraft with highemulation of V-22 Osprey that has same flight characteristics and can beshrunk to a toy specification.

To be a real aircraft has to take many factors into account, such as:the fuselage must have space to accommodate a certain number ofpassengers or cargos, strong power to carry the loads to fly at highspeed; the hull must be sealed and can withstand high pressure at highaltitudes; the fuselage has to arrange complex electric control circuitsand wiring, etc. However, a model aircraft does not need to considerthose factors. Its casing and frame can be made of light PVC material,and the interior space can be fully used for installing electric ormechanical structures without carrying people or cargos. The enginepower merely has to meet flight requirement. Considering the aforesaiddifferences of the real aircraft and model aircraft, the presentinvention provides a VTOL model aircraft that includes a fuselage, twofixed wings extended outwards from two sides of the fuselage, and a tailwing at the tail of the fuselage. Each of the two wings has a distal endequipped with a propeller engine. The two propeller engines respectivelyhave a rotor rotating in opposite directions. The invention also has arotary axle mechanism coupled with the wings in an integrated manner.The fuselage also holds a rotary axle driving means to drive the rotaryaxle mechanism and the propeller engines at two ends thereof to turnconcurrently between the vertical direction and horizontal direction.

The present invention employs the propeller engine to replace theturbine engine of the real aircraft. Because the model aircraft has alight weight and does not need to carry people or cargos, the propellerengine can provide adequate power to meet requirements of verticaltake-off and landing and cruise. The fuselage of the model aircraft alsodoes not need to leave space for accommodating people or cargos, hencethe rotary axle driving means can be directly installed in the fuselageto directly drive the rotary axle mechanism and the two propellerengines to turn concurrently between the vertical direction andhorizontal direction. The rotary axle mechanism is located transverselyacross the fuselage and wings, and provides mechanical and synchronousrotation of the propeller engines. Compared with the real aircraft thatneeds to install a rotor tilt system assembly on the distal end of thewing, the present invention provides a much simplified structure withoutcomplex electrical control synchronous mechanism.

When the propeller engines of the model aircraft of the invention are inthe vertical condition, the pitch of the propeller can be changed toallow the aircraft to perform vertical take-off and landing, and hoverin the air. By changing the tilt direction of the rotor shaft and pitch,the aircraft can fly forwards and backwards, and crab. When thepropeller engines are turned to the horizontal condition and the pitchof each propeller engine can be fixed at a selected value, cruisingflight can be performed. Thus the model aircraft of the invention canfunction and operate like a real V22 Osprey aircraft to achieve highemulation. By incorporating the characteristics of the model aircraft,the invention simplifies the driving means of the real aircraft with anovel driving structure adapted to the size of the model aircraft at ashrunk size within 0.5 to 3 meters. Compared with the conventional modelaircraft that partly imitates V22 Osprey aircraft or only imitates theprofile of V22 Osprey aircraft, the present invention provides a fullimitation design with substantial features and outstanding improvements.

The foregoing, as well as additional objects, features and advantages ofthe invention will be more readily apparent from the following detaileddescription, which proceeds with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of the model aircraft of the invention in avertical take-off and landing or hover condition.

FIG. 2 is a schematic view of the internal structure of the inventionaccording to FIG. 1.

FIG. 3 is a schematic view of the invention in a cruising flightcondition.

FIG. 4 is an enlarged view of a propeller engine.

FIG. 5 is an exploded view of a propeller engine.

FIG. 6 is an enlarged view of a rotary oblique plate.

FIG. 7A is a schematic view of the propeller engine according to FIG. 1in an operating condition.

FIG. 7B is a fragmentary enlarged view according to FIG. 7A.

FIG. 8A is another fragmentary enlarged view according to FIG. 7A.

FIG. 8B is a yet another fragmentary enlarged view according to FIG. 7A.

FIG. 9 is an exploded view according to FIG. 3.

FIG. 10 is an enlarged view of the rotary axle mechanism.

FIG. 11 is an exploded view of the linkage bar mechanism.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Please refer to FIG. 1, the present invention aims to provide a modelaircraft which includes a fuselage 1, two fixed wings 2 extendedoutwards from two sides of the fuselage 1 and a tail wing 3 located atthe tail of the fuselage 1. The two wings 2 respectively have apropeller engine 4 and 5 at a distal end with a rotor 42 and 52 coupledthereon rotating in opposite directions to offset rotation of thefuselage 1. The aircraft also has wheels 6 respectively located at twosides of the bottom and below the prow. While the model aircraft is invertical take-off and landing, or hover in the air, the propellerengines 4 and 5 are in a working condition. Seeing from the front sideof the aircraft, the rotor rotates clockwise, and the other rotor 52rotates counterclockwise as shown by the arrows in the drawings.Rotation of the rotors 42 and 52 generates an upward pulling force. Byadjusting the rotating pitch of the rotors 42 and 52, the pulling forcecan be adjusted. When the pulling force is greater than the gravity ofthe aircraft, the aircraft can take off vertically. When the pullingforce is equal to the gravity the aircraft can hover in the air, andwhen the pulling force is smaller than the gravity the aircraft can becontrolled to land steadily.

Refer to FIG. 2 for the internal structure of the aircraft. Thepropeller engines 4 and 5 include respectively a rotary nacelle 41 and51 with the rotor 42 and 52 at the front end. The rotary nacelles 41 and51 hold a driving mechanism and a pitch control means of the rotors 42and 52, and are coupled to form an integrated body through a rotary axlemechanism 8 connected to the wings 2. The rotary axle mechanism 8transversely stretches over the fuselage 1 which holds a rotary axledriving means 9 to drive the rotary axle mechanism 8 to rotate so thatthe propeller engines 4 and 5 at the two ends thereof can be turnedconcurrently between the vertical direction and horizontal direction.The arrows in the drawings indicate that the propeller engines 4 and 5are rotated from the vertical direction to the horizontal direction.

When the propeller engines 4 and 5 are rotated to the horizontaldirection as shown in FIG. 3, the aircraft is in a cruising flightcondition, and the rotors 42 and 52 are latched at a selected pitch. Thepulling force generated by the rotation is changed to forward thrustforce to drive the aircraft to fly in the cruising flight condition. Insuch a condition, like an ordinary fixed-wing model aircraft, flightcondition is controlled through ailerons, an elevator and rudders. Asshown in the drawings, an aileron 21 is located at the rear edge of thefixed wing 2 to control transverse manipulation of the aircraft. Thetail wing 3 includes a horizontal tail 31 and vertical tails 32 at twoends of the horizontal tail 31. The horizontal tail 31 has an elevator311 at an upper rear edge. The two vertical tails 32 respectively have arudder 321 at a rear edge. The aileron 21, elevator 311 and rudder 321are controlled respectively through independent cruising controlsteering engines 73, 72 and 71.

In addition to the two types of flight conditions mentioned above, thepropeller engines 4 and 5 also can be rotated to a selected anglerelative to the vertical direction, such as between 10° and 80° in theforward or reverse direction so that desired pitch of the rotors 42 and52 can be adjusted to generate desirable pulling force to realizeforward or backward flying of the aircraft.

Please refer to FIGS. 4 and 5 for the detailed structure of thepropeller engine, the propeller engine 5 is taken as an example. Itincludes the rotary nacelle 51 and rotor 52 at the front end of therotary nacelle 51. The rotor 52 include a central hub 521, three rotorblades 524 and three blade clips 523 which are coupled with the centralhub 521 through three radial rotary shafts 522 which are evenly spacedfrom each other on the circumference of the central hub 521. Each bladeclip 523 has a front end clamping one rotor blade 524 and is turnableabout the radial rotary shaft 522 to alter the pitch of the rotor 52.The central hub 521 also has a rotor shaft 513 extended to the rotarynacelle 51. The driving mechanism includes a motor 511 and a gear set512, and is installed on a distal end of the rotor shaft 513. The pitchcontrol means includes a pitch control steering engine 514, a rotaryoblique plate 53 and a plurality of pulling rods located in the middleof the rotor shaft 513.

Referring to FIG. 6, the rotary oblique plate 53 includes an upper plate532 and a lower plate 531 that are interposed by a coil spring 533 toconnect with the rotor shaft 513 through a spherical hinge 534 in aninclined manner. The coil spring 533 is wedged among the upper plate532, lower plate 531 and spherical hinge 534. The lower plate 531 hastwo turnable nodes 535 on the periphery at the same straight line and atilt control node 536 perpendicular to the straight line where theturnable nodes 535 are located. The turnable nodes 535 are held on arotary seat consisting of two bracing plates 541. The tilt control node536 is connected to the pitch control steering engine 514 through alower pulling rod 542. The upper plate 532 has pitch control nodes 537on the circumference evenly spaced from one another at a number matingthe rotor blades. The blade clip 523 has an eccentric control end 526 onone side. The pitch control nodes 537 and the eccentric control end 526are connected through upper pulling rods 543 with a mating number. Referto FIG. 7A for the assembly structure and FIG. 7B for the couplingstructure after rotated.

Refer to FIG. 7A for the operation principle of the propeller engine.The motor 511 drives the rotor shaft 513 to rotate through the gear set512, and the rotor shaft 513 further drives the three rotor blades 524at the front end thereof to rotate to provide power for take-off,landing, hover and cruising of the aircraft. When the propeller engines4 and 5 are not in the horizontal condition, i.e. during take-off,landing, forward or backward fly or crab, the pitch of the propellerengines 4 and 5 has to be changed to adjust the pulling force of theengines for the aircraft to balance the gravity thereof and to alter theflight condition. Alteration of the pitch of the propeller engines iscontrolled through the pitch control steering engine 514 as shown inFIG. 7A. The pitch control steering engine 514 pulls the lower plate 531braced by the bracing plate 541 through the lower pulling rod 542 asshown in FIG. 8A. The lower plate 531 is tilted to drive the upper plate532 to tilt also, and the upper plate 532 pulls the eccentric controlend 526 on the one side of the blade clip 523 through the upper pullingrod 543 to change the pitch of the rotor blade 524 clamped by the bladeclip 523. When the propeller engines 4 and 5 are in the horizontalcondition, i.e. the aircraft is in the cruising flight condition, thepitch control steering engine 514 controls the pitch of the rotor blade524 at a selected value without changing.

To ensure that the upper plate 532 is tilted upwards only in onedirection, the invention further provides a positioning node 538 on thecircumference of the upper plate 532 corresponding to the tilt controlnode 536 of the lower plate. The positioning node 538 is coupled on therotor shaft 513 through an anchor seat turnable synchronously with therotor shaft 513. The anchor seat includes a coupling member 544 and aholding clip 545 that are coupled in a turnable manner. The assembledstructure is shown in FIG. 8B. The anchor seat and the lower pulling rod542 are located on the same plane. The anchor seat confines the upperplate 532 from tilting to the left and right sides.

Refer to FIG. 9 for the exploded view of the invention. The fuselage 1includes a main body consisting of an upper structure 13, a middlestructure 14 and a lower structure 15. The main body has a front endcoupled with a prow casing 11 through a front frame 12, and a rear endcoupled with the tail wing 3 through a rear frame 16. The lowerstructure 15 has a battery box 18 with a lid 17. The prow casing 11holds a wireless receiving module 19 and its related circuit structures.The rotary axle mechanism 8 and rotary axle driving means 9 areinstalled on the middle structure 14. Detailed structure can be seen inFIG. 10. The rotary axle mechanism 8 includes a rotary axle 81transversely running through the two fixed wings 2, a gear set 82 in themiddle mating the rotary axle driving means 9, and a bracing tube 84 tosupport rotation of the rotary axle 81. The rotary axle 81 has twobearings 85 at two ends. The gear set 82 has a potentiometer 83 locatedthereon to measure turning angle of the rotary axle 81. When changingthe angle of the propeller engines 4 and 5 is needed, the rotary axledriving means 9 drives a screw 91 to rotate, then the screw 91 alsodrives the rotary axle 81 to rotate through the gear set 82, so that therotation angle of the propeller engines 4 and 5 coupled on two ends ofthe rotary axle 81 can be adjusted. The potentiometer 83 can accuratelymeasure the rotation angle of the rotary axle 81. The measured rotationangle is fed back to a control circuit to control the rotary axledriving means 9 to precisely position the rotation angle of thepropeller engines 4 and 5.

The cruising control steering engines 73, 72 and 71 are connected to theaileron 21, elevator 311 and rudder 321 through a linkage bar mechanismshown in FIG. 11. The linkage bar mechanism includes a swing bar 74, anextended pulling rod 75 and a clip sheet 76. The extended pulling rod 75has two ends, one end is coupled with the clip sheet 76 and another endis coupled with the swing bar 74 through spherical hinges. The swing bar74 has another end connected to the cruising control steering engine.The clip sheet 76 is connected to the aileron 21, elevator 311 or rudder321. The aforesaid structure controls vertical take-off and landing andveer of the aircraft during cruising flight.

1. A vertical take-off and landing model aircraft, comprising afuselage, two fixed wings extended outwards from two sides of thefuselage and a tail wing at a tail of the fuselage, wherein: each of thetwo fixed wings includes a propeller engine at a distal end, thepropeller engine being coupled with a rotor, the two rotors rotating inopposite directions, the two propeller engines being coupled with arotary axle mechanism connecting to the wings to form an integratedbody, the fuselage holding a rotary axle driving means to drive therotary axle mechanism to rotate and drive the propeller engines at twoends of the rotary axle mechanism to rotate concurrently between avertical direction and a horizontal direction.
 2. The vertical take-offand landing model aircraft of claim 1, wherein each propeller engineincludes a rotary nacelle and the rotor at a front end of the rotarynacelle, the rotary nacelle holding a driving mechanism and a pitchcontrol means of the rotor.
 3. The vertical take-off and landing modelaircraft of claim 2, wherein the rotor includes a central hub, at leastthree rotor blades and a plurality of blade clips mating the number ofthe rotor blades, the blade clips being coupled with the central hubthrough radial rotary shafts evenly spaced on the circumference of thecentral hub to clamp the rotor blades to rotate to change pitch of therotor; the central hub including a rotor shaft extended into the rotarynacelle, the driving mechanism including a motor and a gear set locatedon a distal end of the rotor shaft, the pitch control means including apitch control steering engine, a rotary oblique plate and a plurality ofpulling rods located in the middle of the rotor shaft.
 4. The verticaltake-off and landing model aircraft of claim 3, wherein the rotaryoblique plate includes an upper plate and a lower plate that are coupledwith the rotor shaft through a spherical hinge in the center in aninclined manner, the lower plate including two turnable nodes on thecircumference located on a same straight line and a tilt control nodeperpendicular to the straight line where the turnable nodes located, theturnable nodes being held on a rotary seat, the tilt control node beingcoupled with the pitch control steering engine through a lower pullingrod; the upper plate including pitch control nodes evenly spaced on thecircumference thereof mating the number of the rotor blades, the bladeclip including an eccentric control end on one side, each pitch controlnode being connected to the eccentric control end through upper pullingrods with a mating number.
 5. The vertical take-off and landing modelaircraft of claim 4, wherein the upper plate includes a positioning nodeon the circumference corresponding to the tilt control node of the lowerplate, the positioning node being coupled on the rotor shaft through ananchor seat turnable synchronously with the rotor shaft, the anchor seatconfining the upper plate from tilting to left and right sides.
 6. Thevertical take-off and landing model aircraft of claim 1, wherein therotary axle mechanism includes a rotary axle transversely runningthrough the two fixed wings and a gear set located in the middle of therotary axle mating the rotary axle driving means, and a bracing tubecoupled on two sides of the rotary axle to support rotation of therotary axle.
 7. The vertical take-off and landing model aircraft ofclaim 6, wherein the gear set includes a potentiometer to measurerotation angle of the rotary axle.
 8. The vertical take-off and landingmodel aircraft of claim 1, wherein each fixed wing includes an aileronat a rear edge thereof to control transverse manipulation of theaircraft, the tail wing including a horizontal tail and vertical tailsat two ends of the horizontal tail, the horizontal tail including anelevator, the two vertical tails respectively including a rudder at arear edge thereof; the aileron, the elevator and the rudders beingcontrolled by independent cruising flight control steering engines. 9.The vertical take-off and landing model aircraft of claim 8, wherein thecruising flight control steering engines are connected to the aileron,the elevator and the rudders through a linkage bar mechanism, thelinkage bar mechanism including a swing bar, an extended pulling rod anda clip sheet, the extended pulling rod including two ends coupled withone end of the clip sheet and one end of the swing bar through sphericalhinges, the swing bar including another end connected to the cruisingflight control steering engine, the clip sheet being connected to theaileron, the elevator or the rudder.